Case history
Case history
A 50-year-old man with a history of sarcoidosis, hypertension, and atrial fibrillation presents to the emergency department with altered mental status and a generalised tonic-clonic seizure. The patient lives in a rural area of northern Florida and occasionally goes out into the woods to hunt. One week prior to presentation, he had been having shortness of breath, malaise, and headaches. In the emergency department, physical examination reveals an elevated temperature (39.5°C). The patient is given paracetamol and an anticonvulsant medication, and is admitted to hospital where serological tests are carried out. A lumbar puncture is also performed, and intravenous vancomycin, ceftriaxone, ampicillin, and aciclovir are initiated. Laboratory studies reveal mild leukocytosis with neutrophilic predominance and mild hyponatremia. Cerebrospinal fluid analysis reveals no abnormalities. The patient tests negative for HIV, West Nile virus, enterovirus, and herpes simplex virus. A brain MRI with gadolinium contrast shows abnormal T2 and fluid-attenuated inversion recovery (FLAIR) signals within bilateral frontal and parietal regions, as well as the basal ganglia and ventricular nuclei. An electroencephalogram demonstrates moderate generalised slowing. Initial EEEV IgM performed at admission is negative, but a repeat EEEV IgM drawn at 3 weeks following admission is positive at 1:32. His initial EEEV IgG was 1:64; at 3 weeks it rises to 1:1024. His St. Louis encephalitis serologies are negative. The patient has a slow recovery and remains hospitalised for 4 weeks. At 6 months, he has some impaired memory, but otherwise no neurological deficits. He remains on an anticonvulsant medication.
Other presentations
Patients may also present with cerebral oedema and intracranial hypertension requiring the placement of an external ventricular device and osmotherapy. Other presentations include aseptic meningitis, disorientation, tremors, psychosis, focal neurological weakness, coma, and multi-organ failure. Haemophagocytic lymphohistiocytosis has been reported in conjunction with acute EEEV infection in an infant.[4] South American EEEV (now known as Madariaga virus [MADV] infection) tends to cause milder disease; however, clinical manifestations can range from no symptoms to febrile illness with or without neurological symptoms (e.g., generalised tonic-clonic seizures, acute disseminated encephalomyelitis, or hemiparesis).
Use of this content is subject to our disclaimer